Lecture 4: Manufacturing Processes

Question 1

What are the types of manufacturing/production process? Explain each of them briefly

Answer 1

●Project: Unique product, general equipment and resources
►the product remains in a fixed location
●Job shop: Unique product, but similar products, similar equipment or functions are grouped together
●Batch: Production in small series, less variation
●Mass/Line: Same products in large amounts, work processes are
arranged according to the progressive steps by which the product is
made
●Continuous : like a line only the flow is continuous (very few/without
interruption) such as liquids

Question 2

Explain project and jobbing production processes in detail. What are the similarities and differences?

Answer 2

Project:
●Large-scale
●One or a few end-items
●Tailored to fit unique requirements
●Clear start and finish
●Buildings, movies, highways, aircraft and vessels

Jobbing:
› Small-scale
› Output is one or a few – often customized - identical
items
› Many change-overs
› Special equipment and machine parts.
e.g cane chair production, bespoke (tailoring)

Differences:
› Jobbing production is often in small scale
› Project production is usually in very large scale.
Similarities:
Products are generally customized

Question 3

Explain batch and mass/line production processes. What are the differences between both of them?

Answer 3

Batch:
●Same production line is used for multiple products
►Set-up or Change-over time between various products
●Jobs follow more-or-less the same line
●Focus more on standardized products
●Bread, beer and dinnerware

Mass:
●Production line produces only a single type of product continuously
►All products follow the same path of activities
●Similar or identical items are produced in high volumes
●Few interruptions / change-overs in the process
●Emphasis operations management efficiency
● Cars, telephones, and packaging lines

Differences:
• The production may be cleaned and reconfigured
between batches in batch production.
• Mass production may achieve a greater scale than
batch production as all equipment can be used at all
times.

Question 4

Explain the continuous production process. What are the similarities and differences compared to mass/line production?

Answer 4

●Products are not discrete (i.e. products only be counted in kilos, litres, meters etc.)
●Similar or identical end products (mass production)
●Clear flow through the process
●The product seldom changes
●Only after packaging the product becomes a discrete unit
●Examples: Chemicals, Fibers, Paper

Differences:
› Continuous production is usually on 24 hours a day while mass production may not be on 24 hours a day.
› Continuous production products are in kilos, liters, meters ect (not in discrete).
Similarity:
- Large amount of outputs

Question 5

Name 4 types of layouts and briefly describe them

Answer 5

●Fixed position layout
►Product remains on one position and production means are brought to the product (e.g. boeing, vessel)
●Functional layout – Work center
►Production means are grouped according to function / specialization (e.g. vehicle repair plant)
●Cellular layout – Manufacturing cell
►Dissimilar production means are grouped to optimize movement of materials, often associated with jobbing or batch production (e.g. gears, machine parts)
●Product layout
►Production means are grouped following the steps of the production process, dedicated product lines, often associated with mass/line and continuous production

Question 6

What is Customer Order Decoupling Point (CODP)?

Answer 6

●Corresponds with the last major stock point in the goods flow
►Deliveries to customers are made from here (where the inventory is positioned in the supply chain)
●It separates order-driven activities from forecast-driven activities
●It creates a certain degree of freedom to optimize the upstream activities independently from irregularities/uncertainties in market demand
●The actual CODP is not always located where you would expect it to be, given all factors influencing it

Question 7

What are the forces for determining CODP?

Answer 7

1) Downstream forces —->
Process constraints:
- Long production lead times
- Poor process control

Delivery service requirements

• Customers desire short lead time
• High delivery reliability

2) Upstream forces
Inventory cost considerations
- Low stocks
- Reduce risk of obsolescence

Product-market constraints

• Irregular market demand
• Customer-specific products

Question 8

What are the advantages and disadvantages of resetting the CODP? Moving forwards vs moving backwards

Answer 8

●“Postponement” (Moving Backward, MTS => ATO):
►Techniques
→ Modular Production
→ Value Added Logistics
►Pros and Cons:
→ Customization (+)
→ Reduced Inventory of end-products (+)
→ Increased Order lead times (–)
●Moving Forward (MTO => ATO):
►Pros and Cons:
→ Increased Efficiencies (+)
→ Reduced Customization (–)
→ Reduced Lead times (+)